/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.sanselan.formats.pnm;

import java.io.IOException;
import java.io.InputStream;

import org.apache.sanselan.ImageFormat;
import org.apache.sanselan.ImageInfo;

public class PBMFileInfo extends FileInfo
{
	public PBMFileInfo(int width, int height, boolean RAWBITS)
	{
		super(width, height, RAWBITS);
	}

	public int getNumComponents()
	{
		return 1;
	}

	public int getBitDepth()
	{
		return 1;
	}

	public ImageFormat getImageType()
	{
		return ImageFormat.IMAGE_FORMAT_PBM;
	}

	public int getColorType()
	{
		return ImageInfo.COLOR_TYPE_BW;
	}

	public String getImageTypeDescription()
	{
		return "PBM: portable bitmap fileformat";
	}

	public String getMIMEType()
	{
		return "image/x-portable-bitmap";
	}

	protected void newline()
	{
		bitcache = 0;
		bits_in_cache = 0;
	}

	
	private int bitcache = 0;
	private int bits_in_cache = 0;

	public int getRGB(InputStream is) throws IOException
	{
		if (bits_in_cache < 1)
		{
			int bits = is.read();
			if (bits < 0)
				throw new IOException("PBM: Unexpected EOF");
			bitcache = 0xff & bits;
			bits_in_cache += 8;
		}

		int bit = 0x1 & (bitcache >> 7);
		bitcache <<= 1;
		bits_in_cache--;

		if (bit == 0)
			return 0xffffffff;
		if (bit == 1)
			return 0xff000000;
		throw new IOException("PBM: bad bit: " + bit);
	}

	public int getRGB(WhiteSpaceReader wsr) throws IOException
	{
		int bit = Integer.parseInt(wsr.readtoWhiteSpace());
		if (bit == 0)
			return 0xff000000;
		if (bit == 1)
			return 0xffffffff;
		throw new IOException("PBM: bad bit: " + bit);
	}

}